A tomographic view of the Gulf Stream southern recirculation gyre at 38°N, 55°W
Chester, David B.
MetadataShow full item record
Reciprocal acoustic transmissions made in a region just south of the Gulf Stream are analyzed to determine the structure and variability of temperature, current velocity, and vorticity fields at the northern extent of the southern recirculation gyre. For ten months (November, 1988 through August, 1989), a pentagonal array of tomographic transceivers was situated in a region centered at 38°N, 55°W as part of the eastern array of the SYNOP (SYNoptic Ocean Prediction) Experiment. The region of focus is one rich in mesoscale energy, with the influence of local Gulf Stream meandering and cold-core ring activity strikingly evident. Daily-averaged acoustic transmissions yielded travel times which were inverted to obtain estimates of range-averaged temperature and current velocity fields, and area-averaged relative vorticity fields. The acoustically determined estimates are consistent with nearby current meter measurements and satellite infrared imagery. The signature of cold-core rings is clearly evident in the sections. Spectral estimates of the fields are dominated by motions with periodicities ranging from 32-128 days. Second-order statistics, such as eddy kinetic energies, and heat and momentum fluxes, are also estimated. The integrating nature of the tomographic measurement has been exploited to shed some light on the radiation of eddy energy from the Gulf Stream. The Eliassen-Palm flux diagnostic has been applied to an investigation of wave radiation from the Gulf Stream. Results of the diagnosis suggest that the Gulf Stream itself is the source of wave energy radiating into the far field and found in the interior of the North Atlantic subtropical gyre.
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 1993
Showing items related by title, author, creator and subject.
Silverthorne, Katherine E. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2010-06)Observational and modeling techniques are employed to investigate the thermal and inertial upper ocean response to wind and buoyancy forcing in the North Atlantic Ocean. First, the seasonal kinetic energy variability of ...
Workman, Rhea K. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2005-06)This thesis uses trace elements and radiogenic isotope tracers to define elemental abundances in reservoirs of the Earth's mantle, including EM2 (the Enriched Mantle 2), as seen in the Samoan hotspot track, and DMM (the ...
Geochemical tools and paleoclimate clues : multi-molecular and isotopic investigations of tropical marine sediments and alpine ice Makou, Matthew C. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2006-02)South American climate has undergone dramatic changes since the last glacial period, as evidenced from Cariaco Basin (Venezuelan coast) and Peru Margin marine sediment biomarker records. Compounds derived from vascular ...